Colorimetrische

Colorimetrische, or colorimetric, designates the measurement and numerical description of color using standardized color spaces and light-measuring instruments. It is a branch of color science that connects physical spectra, material properties, and human color perception to produce objective color values.

Principles: Central to colorimetry is the concept of a standard observer and color matching functions, which describe the response of the human eye to narrow-band light. In practice, three values, called tristimulus values, are used to represent color in a device-independent space such as CIE XYZ. From XYZ, perceptually uniform spaces like CIE L*a*b* or L*u*v* can be derived to provide more intuitive measures of lightness and chroma.

Instruments and methods: Colorimetric measurements are performed with colorimeters or spectrophotometers. Colorimeters use filtered detectors to approximate three primaries, while spectrophotometers measure the full spectral power distribution and compute color coordinates for any illuminant. Measurements typically involve reference white and neutral gray standards; illuminants like D65 are used to simulate daylight. Metamerism—colors that match under one light but not another—is a known limitation.

Applications and history: Colorimetry is essential in printing, textiles, paints, plastics, electronics displays, lighting, and quality control to ensure consistent appearance. The modern framework was established in the 1930s by the CIE, with the XYZ color space and standard observer enabling cross-material and cross-device comparisons. Ongoing developments include more perceptually uniform color models and device calibration techniques.